1. Field of the Invention
The present invention relates to a bumper device of a robot cleaner and a robot cleaner having the same and, more particularly, to a bumper device of a robot cleaner capable of buffering an impact applied to any portion of an outer surface of a main body of a robot cleaner, and stopping an operation or changing a running direction by sensing the generation of the impact, and a robot cleaner having the same.
2. Description of the Related Art
In general, a robot cleaner is a device that senses a cleaning region and an obstacle by using a sensor according to a command of a controller and automatically performs cleaning by traveling in the cleaning region. When power of a battery provided in the device is used up, the device moves to a charging stand installed at a certain position for its charging, and when charging is completed, the device resumes cleaning.
Usually, the robot cleaner senses existence of an obstacle in the cleaning area before traveling and performs cleaning, but it may collide with an obstacle that has not been previously sensed during its traveling according to circumstances.
When the robot cleaner collies with the obstacle, a bumper installed at a front side of a main body of the robot cleaner buffers it, and at the same time, a controller senses it and controls the robot cleaner to run by evading the obstacle.
A related art robot cleaner having the buffer device will now be described with reference to the accompanying drawings.
FIG. 1 is a perspective view of a robot cleaner having a bumper device according to a related art, FIG. 2 is a sectional view taken along line A-A of the bumper device in FIG. 1 without having an impact applied thereto, and FIG. 3 is a sectional view taken along line A-A of the bumper device to which an impact has been applied.
With reference to FIG. 1, the related art robot cleaner 1 having the bumper device 30 includes a robot cleaner main body 10 having a suction opening (not shown) for sucking dust or debris from a floor of a room or the like, a driving wheel 20 installed at a lower portion of the main body 10 and enabling the robot cleaner to travel around, and a bumper device 30 coupled at a front side of the main body is 10 and buffering an impact applied to the main body 10 when the robot cleaner collides with an obstacle.
With reference to FIG. 2, the robot cleaner main body 10 includes projection parts 11 protruded from outer side of the main body 10 to allow the bumper device 30 to be mounted, and fixing protrusions 11a formed at an end portion of the projection parts 11 to fix the bumper unit 30 so that it cannot be released.
The bumper device 20 includes a bumper case 31 for forming the exterior, hooking portions 31a caught by the fixing protrusions 11a of the projection parts 11 of the main body 10, a micro-switch 32 having a contact terminal 32a protruded to outward direction of the main body 10 and sensing a collision, and a contact protrusion 33 formed at an inner side of the bumper case 31 and contacting with the contact terminal 32a of the micro-switch 32 in occurrence of a collision with an obstacle.
The bumper device 30 additionally includes a pair of springs 34 coupled between an inner surface of the bumper case 31 and an outer surface of the main body 10 to buffer an external impact, and returning the bumper case 31 to its original state when the impact dissolves, and a coupling part 34a for coupling the springs 34 between the inner surface of the bumper case 31 and the outer surface of the main body 10.
The operation of the related robot cleaner 1 having the bumper device 30 will now be described.
With reference to FIG. 1, when the robot cleaner is turned on, it travels in a cleaning region according to rotation of the driving wheel 20, sucking dust or debris from the floor by a suction force of a fan motor (not shown) so as to be collected into a filter (not shown).
With reference to FIGS. 2 and 3, when the robot cleaner collides with an obstacle 80, a corresponding impact applied to the bumper device 30 is buffered by the springs 34 installed between the bumper case 31 and the main body 10 of the robot cleaner, to thus prevent transferring of the impact to an internal component of he main body of the robot cleaner.
At the same time, the bumper case 31 is slidably pushed toward the main body 10 of the robot cleaner, making the contact protrusion 33 formed at the inner side of the bumper case 31 contact with the contact terminal 32a of the micro-switch 32.
Then, the micro-switch 32 transmits a signal to a controller (not shown), and the controller allow the robot cleaner to perform cleaning by avoiding the obstacle 80.
However, the related art bumper device 30 has the problem that the buffering and collision sensing can be performed only when an impact is applied to the front side of the main body 10 of the robot cleaner. In addition, its construction is so complicate that a volume and weight of the main body 10 increase and its cost is also increased.
As one method for solving the problems, installation of several micro-switches along a circumferential surface of the main body 10 of the robot cleaner can be considered, but problems arise that a cost incurs for installing several micro-switches to increase the expense and a wiring structure for connecting the several micro-switches becomes complicate.